1. Field of the Invention
The present general inventive concept relates to a method of transmitting data more effectively and an apparatus to do the same, and more particularly, to a method of classifying service traffic, transmitting data according to the classifications of the service traffic, and allocating channels to transmit data in a power line communication (PLC) network, and an apparatus to do the same.
2. Description of the Related Art
A power line communication (PLC) network provides a variety of service traffic such as a signaling service, a voice over Internet protocol (VoIP) service, a video conferencing service, an audio-video (AV) streaming service, an electronic commerce service, a web browsing service, a Telnet service, a default data service, an e-mail service, a download service, etc. Each different type of service traffic has different characteristics and different levels of importance based on those characteristics. For example, whether to provide a service in real-time is the most important service traffic characteristic in the VoIP service or in the video conferencing service. However, whether to provide service in real-time is a less important service traffic characteristic in the default data service or the e-mail service than in the VoIP service or the video conferencing service.
Error sensitivity of service traffic is the most important service traffic characteristic in the electronic commerce service or web-browsing service, whereas it is a relatively less important service traffic characteristic in the AV streaming service.
Allowable delay of service traffic is the most important service traffic characteristic in the VoIP service or in the electronic commerce service, whereas it is a relatively less important service traffic characteristic in the Telnet service.
Each of the service traffic characteristics can have relative priority based on their importance. For example, whether to provide service in real-time is considered prior to the error sensitivity of service traffic. In detail, a service, whose most important service traffic characteristic is whether to provide a service in real-time, is provided prior to a service having the error sensitivity of service traffic as the most important service traffic characteristic. Accordingly, data of a service whose most important service traffic characteristic is whether to provide a service in real-time, is transmitted or allocated by a channel prior to data of a service having as a less important service traffic characteristic, whether to provide service in real-time. When various types of data are transmitted via a limited channel bandwidth, each type of data is sequentially transmitted after allocating a channel bandwidth to each type of data.
However, if the data is transmitted based only on a buffer input order without a specific standard, since differentiated quality of service (QoS) is not provided according to the service traffic characteristics, the data cannot be effectively transmitted. For example, if the VoIP service or the video conferencing service having whether to provide data in real-time as the important service traffic characteristic is not prior to the e-mail service or the download service in the transmission of data and the allocation of channels, since the VoIP service or the video conferencing service is not prior to the e-mail service or the download service in a processing order or the buffer input order, it is impossible to provide the differentiated QoS satisfying each of the service characteristics.
Conventionally, attempts to determine data transmission priority have been made using a virtual local area network (VLAN) tag user priority information field defined in the IEEE 802.3P/Q, a differentiated services code point (DSCP) field that is QoS information used in a DiffServ per-hop forwarding behavior (DiffServ PHB) service, or a DLNAQOS_UP field that is QoS information provided by the digital living network association guidelines. However, since these attempts do not classify priority information according to the service traffic characteristics and do not divide priorities into sub-priorities, they cannot properly reflect the service traffic characteristics. In detail, since priority for the transmission of data or allocation of channels is not determined based on the service traffic characteristics, it is impossible to provide differentiated QoS according to types of services, and thus it is impossible to more effectively transmit data. Therefore, it is necessary to classify service traffics and sequentially transmit data based on the classified priority or allocate data transmission channels in order to provide the differentiated QoS according to service characteristics in a PLC network.